3.8.1 REST error: LastUpdated: Immutable Field

Assuming a ticket 1 with a multi-valued CF currently with one value
"a", try this via REST

/usr/local/data/rt/bin/rt edit ticket/1 del ‘cf.{test3}=a’

This works but also returns the error

LastUpdated: Immutable field

Only seems to do this with the command-line “add” and “del” commands
but not “set”.

I looked at the code but it’s not obvious what’s going wrong here. My
best guess is that SetLastUpdated is getting called twice rapidly in
succession and the second call is hitting a DB lock put on by the
first call? Doesn’t explain why it’s being called twice but it seemed
to be when I traced it.

Dr Philip Kime